Name: ________________________________________________ Assignment Due Date: February 17, 2012

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AP Physics: Center of Mass Calculations and Intro to Momentum

Multiple ChoiceIdentify the choice that best completes the statement or answers the question.

____ 1. The mass of the rectangle in the figure is M, the mass of the ring is M, and the mass of the circle is 3M The center of mass of the system with respect to the origin 0 is located at point

a. 1 d. 4b. 2 e. 5c. 3

____ 2. An L-shaped piece, represented by the shaded area on the figure, is cut from a metal plate of uniform thickness. The point that corresponds to the center of mass of the L-shaped piece is

a. 1 d. 4b. 2 e. 5c. 3

Name: ________________________

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____ 3. The center of mass of the system of particles shown in the diagram is at point

a. 1 d. 4b. 2 e. 5c. 3

____ 4. The SI units of momentum area. kg·m·s d. kg/Jb. m2/s e. kg·m/sc. kg·s/m

Short Answer

5. Why does a wine glass survive a fall onto a carpet but not onto a concrete floor?

Problem

6. Three point masses of 2 kg each are located on the x axis at the origin, x = 0.20 m, and x = 0.50 m. Find the center of mass of the system.

Name: ________________________

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7. A 24-kg child is 20 m from an 86-kg adult. Where is the center of mass of this system?

8. Three objects of 2 kg each are located in the xy plane at points (10 cm, 0), (0, 10 cm), and (10 cm, 10 cm). Find the location of the center of mass.

9. Find the center of mass xcm of the three masses in the figure below.

Name: ________________________

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10. Alley Oop's club-ax consists of a symmetrical 8-kg stone attached to the end of a uniform 2.5-kg stick that is 98cm long. The dimensions of the club-ax are shown in the figure below. How far is the center of mass from the handle end of the club-ax?

11. The uniform sheet of plywood in the figure below has a mass of 20 kg. Find its center of mass.

Name: ________________________

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12. A 1500-kg car is moving westward with a speed of 20 m/s, and a 3000-kg truck is traveling east with a speed of 16 m/s. Find the velocity of the center of mass of the system.

13. A girl of mass 55 kg jumps off the bow of a 75-kg canoe that is initially at rest. If her velocity is 2.5 m/s to the right, what is the velocity of the canoe after she jumps?

14. Two masses of 5 kg and 10 kg are connected by a compressed spring and rest on a frictionless table. After the spring is released, the smaller mass has a velocity of 8 m/s to the left. What is the velocity of the larger mass?

15. A soccer ball of mass 0.43 kg leaves the foot of the kicker with an initial speed of 25 m/s. (a)What is the impulse imparted to the ball by the kicker? (b) If the foot of the kicker is in contact with the ball for 0.008 s, what is the average force exerted by the foot on the ball?

ID: A

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AP Physics: Center of Mass Calculations and Intro to Momentum

Answer Section

MULTIPLE CHOICE

1. ANS: B REF: Tipler 4th ed Mult Choice Question Bank p.115 #1 2. ANS: D REF: Tipler 4th ed Mult Choice Question Bank p.115 #2 3. ANS: B REF: Tipler 4th ed Mult Choice Question Bank p.117 #5 4. ANS: E REF: Tipler 4th ed Mult Choice Question Bank p.120 #14

SHORT ANSWER

5. ANS:

REF: Tipler 4th ed. p.249 #44

PROBLEM

6. ANS:

REF: Tipler 4th ed. p.246 #2

ID: A

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7. ANS:

REF: Tipler 4th ed. p.246 #3 8. ANS:

REF: Tipler 4th ed. p.246 #4 9. ANS:

REF: Tipler 4th ed. p.246 #5 10. ANS:

REF: Tipler 4th ed. p.246 #6 11. ANS:

REF: Tipler 4th ed. p.247 #9 12. ANS:

REF: Tipler 4th ed. p.247 #19 13. ANS:

REF: Tipler 4th ed. p.248 #31

ID: A

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14. ANS:

REF: Tipler 4th ed. p.248 #32 15. ANS:

REF: Tipler 4th ed. p.249 #45